The rust of linseed and flax can be completely controlled by spray of

✅ Explanation: Borax is a boron-containing compound that has been found to be effective in controlling rust of linseed and flax caused by Melampsora lini. It acts as a fungicide by disrupting the fungal cell membranes and inhibiting spore germination.

📌 Other Options Explanations:
-(b) Dithane M-45: This is a broad-spectrum fungicide commonly used to control various fungal diseases.
-(c) Vitavax: Vitavax (carboxin) is a systemic fungicide often used for seed treatment and control of soil-borne diseases.
-(d) Agrosan GN: Agrosan GN is a fungicide primarily used for seed treatment and control of seed-borne diseases.

🔑Key Points:
-The rust of linseed and flax can be completely controlled by a spray of Borax.Melampsora lini, while of economic importance as the causal agent of rust disease of flax and linseed.
-Borax can remove rust from outdoor furniture, household appliances, garden equipment, metal surfaces, and more. Mixed with warm water and lemon juice, Borax becomes a paste. Leave the paste on for at least 20 minutes, then wipe off the rust.